<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>client</title>
</head>
<body>
	<iframe src="http://localhost:8081/data.html" style='display: none;'></iframe>
	<script>
		window.onload = function() {
			let targetOrigin = 'http://localhost:8081';
			window.frames[0].postMessage('index.html 的 data!', targetOrigin);
		}
		window.addEventListener('message', function(e) {
			console.log('index.html 接收到的消息:', e.data);
		});
	</script>
</body>
</html>